TY - JOUR
T1 - Investigation of microstructure and hydrogen absorption properties of bulk immiscible AgRh alloy nanoparticles
AU - Tayal, Akhil
AU - Seo, Okkyun
AU - Kim, Jaemyung
AU - Kusada, Kohei
AU - Kobayashi, Hirokazu
AU - Kitagawa, Hiroshi
AU - Sakata, Osami
N1 - Funding Information:
The authors acknowledge Dr. Wolfgang Caliebe and Dr. Vadim Murzin for their help during the XAFS measurements. This project is partially funded by ACCEL ( JPMJAC1501 ) and Japan Society for the Promotion of Science (JSPS) KAKENHI No. 18K04868 and 20K15083 . We thank Andrew Jackson, Ph.D., from Edanz Group (https://en-author-services.edanzgroup.com/ac) for editing a draft of this manuscript.
Publisher Copyright:
© 2021 The Authors
PY - 2021/7/15
Y1 - 2021/7/15
N2 - Bimetallic alloy nanoparticles (NPs) exhibit superior catalytic and chemical storage properties relative to the monometallic NPs. Previously, it has been reported that bimetallic AgRh forms solid-solution alloy NPs that have unusual hydrogen storage properties not commonly observed in individual Ag and Rh NPs. Here, we use a combination of X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS) techniques to investigate the microstructure and unique hydrogen absorption properties of bulk immiscible AgRh alloy NPs. XRD analysis reveals that the long-range structure of the alloy sample can be estimated as a single fcc phase with a slightly smaller lattice parameter than that of the bulk Ag and larger than that of bulk Rh. XAFS analysis reveals that charge transfer between Rh and Ag occurs in this interfacial region. The near-edge profile reveals a variety of local environments for Ag and Rh, including distinct atomic pair distances and disorder. The atomic pair distances were compressed around Ag and elongated around Rh. A substantial fraction of the sample is an alloy phase formed by mixing of nano/sub-nanosized domains of Rh and Ag NPs. Mixing at the atomic level mainly occurs in the interfacial region. Consequently, the interfacial region has an important influence over the microstructure and provides active sites for hydrogen absorption.
AB - Bimetallic alloy nanoparticles (NPs) exhibit superior catalytic and chemical storage properties relative to the monometallic NPs. Previously, it has been reported that bimetallic AgRh forms solid-solution alloy NPs that have unusual hydrogen storage properties not commonly observed in individual Ag and Rh NPs. Here, we use a combination of X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS) techniques to investigate the microstructure and unique hydrogen absorption properties of bulk immiscible AgRh alloy NPs. XRD analysis reveals that the long-range structure of the alloy sample can be estimated as a single fcc phase with a slightly smaller lattice parameter than that of the bulk Ag and larger than that of bulk Rh. XAFS analysis reveals that charge transfer between Rh and Ag occurs in this interfacial region. The near-edge profile reveals a variety of local environments for Ag and Rh, including distinct atomic pair distances and disorder. The atomic pair distances were compressed around Ag and elongated around Rh. A substantial fraction of the sample is an alloy phase formed by mixing of nano/sub-nanosized domains of Rh and Ag NPs. Mixing at the atomic level mainly occurs in the interfacial region. Consequently, the interfacial region has an important influence over the microstructure and provides active sites for hydrogen absorption.
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U2 - 10.1016/j.jallcom.2021.159268
DO - 10.1016/j.jallcom.2021.159268
M3 - Article
AN - SCOPUS:85101740763
VL - 869
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
M1 - 159268
ER -